Diesel fuel



Patented Apr. 26', 1935 UNITED STATES PATENT "OFFICE DIESELFUEL Robert C. Moran, Wenonah, and Darwin E. Bllertscher, Woodbury, N. 1., usignors to Socony-Vacnnm Oil Company, Incorporated, New York, N. Y., a corporation of New Xork.

No Drawing. Application January 23, 1936,

Serial No. 60,448

4 Claims- (01. 44-9) This invention tlo do with fuels for internal has the same combustion characteristics as the combustion engines ofithe Diesel type, andis fuel under test. (Boerlage and Broeze. J. Soc. concerned with-the modification of such fuels Automotive Eng. 31, 282-93 (1932)). Anincrease by the addition 'of characterizing ingredientsfor in cetene number indicates a decrease in delay 5 the purpose of modifying and/or controlling the between fuel injection and fuel ignition and con- 5 combustion characteristics of the fuel. sequently indicates a betterment in fuel com- The requirements of a Diesel cycle call for a bustion characteristics. In fuels of gasoline nafuel whose ignition and combustion characterture intended for Diesel use, it is probably more istics are the opposite of those usually desired in convenient, at least at present, to express the 10. an Otto cycle internal combustion engine as characteristics by means of octane number, typified by ,,the usual spark-ignition gasoline wherein a decrease would indicate improvement engine. The {desired combustion in an ordinary in quality" of fuel for Diesel engine use. Both gasoline engine is one of a controlled or con- .methods of evaluation are hereinafter made trollable slowness, since too rapid ignition causes use of.'

the phenomena usually characterized by the in-'*' "According to the present invention, Diesel fuels 5 elusive term "knocking". In the Diesel cycle, the may be altered in combustion characteristics by desired characteristics are diametrically opposite, the addition of small amounts of oil-soluble triand enhanced speed of ignition is desired. Here azo organic compounds. As examples of some the fuel is injected into a combustion space and of the members of this group which have been it may exert maximum emciency only when the found efiective, there are noted the following: 20 delay period between injection and ignition is Triazo-acetone, B-triazo-ethanol, ethyl-tiiazoas short as possible. Improperly delayed igniformate, B-triazo-ethyl triazo-acetate, and *1:2 tion in a Diesel engine also gives'rise to phediazldo ethane. nomena known as knocking", due to improper The triazo compounds constitute a well-known coordination of combustion phenomena and cylgroup of organic chemical compounds, character- 25 inder conditions,'although the reason for such. ized by the presence of the monovalent triazo knocking is the reverse of that for knocking in group gasoline engines of ordinary type. N

This invention has to do with the useof novel g i characterizing ingredients in Diesel fuel tending 30 to promote rapidity of combustion and so control the characteristics of the fuel. A general discussion of-the group together with This invention has for its bject the improvesome notes as to synthesisof members thereof, ment of Diesel fuels by the'addition of certain will be found in Bernthsen (Sudburough) Textcompounds whose presence in small quantities book of Organic Chemistry, edition 1930, D. 35 promotes the rapidity of combustion of such fuels. Van Nostrand 00., pages 869, 870, 871. More The novel Diesel fuels herein disclosed are complete directions-for the synthesis of certain characterized by the presence of small amounts members of the group, particularly those memof organic azido-derivatives, that is triazo combers whose properties as Diesel fuel improvers are 4.0 pounds, as combustion accelerators, and comprise set forth below, will be found as follows: 40

not only the distillates of the kerosene-like boiling range commonly denoted as Diesel fuel, but Ethyl gg g g gg extend as well into the field of hydrocarbon prod- Ethyitnazomrmate Ibid page ucts both heavier and lighter; as, for example, Triazdacetofie Ibid' page 81 light and heavy fuel oils for use in Diesei engimlis' 1"2 Bistriazoethane Forster Flerz 8: Joshua I and gasoline for use in Diesel cycle gasoline (r2 mazidoethane) Ibid 1070 (1908) engines. a r Knocking characteristics of gasoline for use in gigggg'ggfigigg; 22 :3; a Otto cycle engines of ordinarytype are normally actate' 95 201 (1909) 59 expressed in terms of octane number, after an 60 accepted usage in the art. Knocking character- As an example of the eflicacy of these inistics of Diesel fuels are at present best expressed gredients the following data is given, in which by cetene numbers. The cetene number is the the indicated percentages of the indicated comper cent by volume of cetene in a blend of cetene pounds were added to a distillate. Diesel fuel of and alphamethylnaphthalene, which blended fuel the type commonly known as No. 2 furnace oil, 55

having a gravity of 36.9 A. P. I., a 10% A. S. T. M. distillation point of 404 F., and a 90% point of Tests in Diesel fuel Compound Percent Organs No.

Eth l-triaso formats l 2 1:2 iasido ethane l 4 Octane No.

Compound m docrem From the above data it may be seen that novel ingredients herein proposed are effective for the purpose intended, namely that-of promoting the combustion of mineral hydrocarbons in a manner capable of increasing their suitability for use in internal combustion engines of the Diesel type.

The above compounds are identified by the presence of the monovalent -N: radical and are spoken of as azido or triazo compounds. Other members of the group which are useful for the purposes of this invention are triazoacetic acid, tria zoacetamide, triazoformic acid, trlazopropionic acid, allyl azolmide, ethyl esters of the several-triazo acids, esters of the several triazo acids and trlazoethanol, and other azido derivatives of the aliphatic hydrocarbons, as triazoethylene. In general, only those azido or triazo derivatives of compounds of relatively low molecular weight are preferred, the influence of the Na radical disappearing rapidly with increases in the molecular weight of the compounds into which it is substituted, certain triaz'oethanol esters of aromatic acids being entirely without effect. Among the group of compounds generally found useful, preference ishad for those containing relatively great amounts of the --N: radical, as, for example the esters of triazo ethanol and triazo acids, low molecular weight triazo ketones and triazo acids, and more partlclarly the triazo derivatives of lower aliphatic hydrocarbons, as diazido ethane and triazo ethylene. In general terms, sufficiently great proportion of the N: radical is pr t for the purposes of this invention in those azi substituted aliphatic compounds of the vario classes having from two to five carbon atoms, inclusive. Y

These compounds may be used in percentages up to about ten per cent of the fuel, but in general, lower concentrations are sufllciently effective, and under normal conditions, not more than five per cent of the preferred members will be necessary to bring about substantial improvement in the fuel as expressed'by decrease in ignition delay period.

In the following claims, the term Diesel fuel A means any, and includes all types of hydrocarbon products intended for use in any engine operating according to theDlesel cycle.

We claim:

1. An improved Diesel fuel, comprising a liquid hydrocarbon fuel and in admixture therewith a minor proportion, sumcient to decrease the ignition delay period of the fuel, of one or more compounds selected from the group consisting of triazo-acetone, triazoethanol, ethyl-triazo formate, triazo-ethyl-triazo acetate, and 1:2 diazido ethane.

2. An improved Diesel fuel', comprising a liquid hydrocarbon fuel and in admixture therewith a minor proportion, suflicient to decrease the ignition delay period of the fuel, of 1 :2 diazido ethane.

3. An improved Diesel fuel, comprising a liquid hydrocarbon fuel and in admixture therewith a minor proportion, sufllcient to decrease the ignition delay period of the fuel, of ethyl triazo formate.

4. An improved Diesel fuel, comprising a liquid hydrocarbon fuel and in admixture therewith a minor proportion-,"sufllcient to decrease the ignition delay period of the fuel, of triazo acetone.

ROBERT C. MORAN. DARWIN E. BADERTSCHER. 

